The field of GOP presidential candidates angling to take your job has shifted considerably. Congress is growing impatient with the pace of withdrawing American troops from Afghanistan. And the mess over the federal debt limit remains, well, messy.

Spring storms have taken a steep toll in the South and Midwest. World events have competed for public attention, including the capture of alleged war criminal Ratko Mladic and the stepped-up NATO-led bombing campaign in Libya.

There has been good news for you, as well. Democrats won a special House election in New York that was seen as a fine omen for your party's prospects in 2012. Word came that Chrysler had paid back most of the loan money your administration orchestrated. And the Patriot Act to fight terrorism was renewed just in time for you to sign it into law — from afar by autopen.

None of this news has been lost on Obama as he has traveled Europe. He's kept a watchful eye on events at home as he's devoted the week to the business of strengthening relationships with Western allies and marshaling support for democratic stirrings in the Middle East and North Africa. On Friday he arrived in Poland, the final stop on his itinerary, to connect with an ally that has sometimes felt slighted and to underscore the growing importance of Central and Eastern Europe in world affairs.

Obama will hold two days of political meetings focusing on security, energy and joint U.S.-Polish efforts to promote democracy in North Africa, Belarus and elsewhere in Eastern Europe. But unlike past U.S. presidents who visited this nation of 38 million, Obama will not meet or address the Polish public directly. He opened the visit by spending time at a memorial to those slain in the Warsaw Ghetto uprising against Nazis, meeting Holocaust survivors and leaders of Poland's Jewish community.

Earlier Friday, Obama wound up his work at a two-day summit of the Group of Eight industrialized nations in France, where leaders agreed to support the Arab Spring movement, but in a way that underscores the financial pressures being felt in the United States and other developed nations. The countries aim to provide $40 billion for the Arab nations but didn't say where the money would come from or specify what it would be for.

The meeting was more about fostering trade than aid, and more about encouraging investment than assistance, U.S. officials said.

Each stop on the president's four-nation trip was calibrated to achieve both foreign and domestic objectives.

Overall, it may well be the visuals from Obama's trip — and the fact that he showed up and broke bread with Western allies — that endure longer than the words he spoke. Forced to compete for attention with a host of events in the U.S. and elsewhere, Obama tried to use his trip to cement old friendships, strengthen alliances for future world challenges and sync up with voters back home.

His first stop, in Ireland, was as much about finding common ground with Americans as it was about connecting with the Irish. In a quick trip to the tiny village where his great-great-great grandfather once lived and in a rousing speech to tens of thousands in Dublin, the president whose very birth in the United States has been called into question by skeptics was able to identify himself with the tens of millions of Americans who claim Irish ancestry and the legions more who identify with the immigrant experience.

The resulting images — more memorable than anything Obama said — were political currency for a president who also happens to be a candidate for re-election. There he was, raising a pint with the locals in the friendly intimacy of a village pub and standing before adoring thousands for a presidential speech that looked more like a campaign rally.

Next stop: London, where the president tended to important work shoring up the U.S. partnership with its most important ally. The president devoted two days to the pomp and ceremony of a state visit with Queen Elizabeth II and to strengthening ties with British Prime Minister David Cameron, who proved a better foreign policy ally than ping pong partner when he and Obama visited a local school and grabbed a couple of paddles.

The president whose grandfather was a Kenyan cook in the British army stood in the august setting of Westminster Hall and gave what amounted to a rousing pep talk for the trans-Atlantic partnership, insisting it's still relevant and robust in a day when countries like China, India and Brazil are growing in power and influence.

Obama's would-be challengers in the GOP field were happy to offer their own thoughts on the president's European tour, and remind him of the political and budget battles afoot back home. Former Minnesota Gov. Tim Pawlenty, who joined the presidential field this week, tweeted at Obama: "sorry to interrupt your European pub crawl, but what was your Medicare plan?"

It was a sharp reminder of the ongoing budget battles at home and the way resurgent Republicans have effectively pushed the president to the right in the debate over spending and deficits.

Obama's focus pivoted to foreign policy matters as his trip progressed. In France, he huddled with Russian President Dmitry Medvedev on the thorny matter of U.S. plans for a missile defense program in Central and Eastern Europe that makes the Russians nervous, and had to be satisfied with progress made rather than a breakthrough.

The president's visit to Poland coincided with a conference there of Central and Eastern European Union leaders, and Obama hoped to hold out their experiences with transitioning to democracy as offering real-life lessons to those seeking freedoms across North Africa and the Middle East.

At every stop on Obama's trip, the president was careful to telegraph his involvement in events at home.

He was up early at the U.S. ambassador's residence in London to make a public statement about the devastating tornadoes in Missouri and to promise he'd be there for a visit on Sunday. He heralded the payback of the Chrysler bailout, and scheduled a visit to a Chrysler plant in Ohio next week. After a bilateral meeting with French President Nicolas Sarkozy, he welcomed the renewal of the Patriot Act as an important tool for fighting terrorism.

By the day, the field of challengers vying to run against Obama shifted over the past week: Mitch Daniels said he wouldn't run. Pawlenty got in the race. Rick Santorum said he'd join next month. Mitt Romney said he'd officially become a candidate next week. Sarah Palin announced an East Coast bus tour that stirred speculation. Texas Gov. Rick Perry said he might get in. Minnesota Rep. Michele Bachmann said she'd decide next month.

Obama comes home to all this on Saturday night.

Then it's a quick pivot to domestic concerns.

By Sunday, he'll be in Missouri to meet with people affected by the tornadoes.